Impact of orthodontic correction of dental crowding with pre-molar extraction in the anterior mandible evaluated by cone-beam computed tomography.

INTRODUCTION: To evaluate, by cone-beam computed tomography (CBCT), the change in thickness and height of the alveolar bone and interdental septum in the anterior mandible after orthodontic treatment for dental crowding using tooth extraction. MATERIAL AND METHODS: The sample consisted of 48 mandibular incisors from adult patients who presented with Class I malocclusion and required orthodontic treatment with the extraction of mandibular premolars. CBCT images were taken before starting the treatment (T1) and three months after treatment (T2). The following measurements were evaluated: width and height of the alveolar bone and the interdental septum, the distance between the cementoenamel junction and the bone ridges (F-CEJ-MBC and L-CEJ-MBC), as well as the vertical positioning and inclination of the incisor, using the Lingual Plane as the reference point. The paired Student's t-test and Pearson correlation were used with a significance level of 5%. RESULTS: A significant increase was observed in the distance L-CEJ-MBC, which shows the appearance of bone dehiscence. The degree of dental crowding was not a risk factor for the development of dehiscence. The decrease in the incisor inclination and intrusion was related to the formation of dehiscence on the lingual surface. CONCLUSION: The variation in the incisor's inclination and intrusion during the treatment of dental crowding using tooth extraction are related to the formation of bone dehiscence on its lingual surface.

The use of digital periapical radiographs to study the prevalence of alveolar domes.

PURPOSE: In the present study, we coined the term 'alveolar dome' and aimed to demonstrate the prevalence of alveolar domes through digital periapical radiographs. MATERIALS AND METHODS: This study examined 800 digital periapical radiographs in regard to the presence of alveolar domes. The periapical radiographs were acquired by a digital system using a photostimulable phosphor (PSP) plate. The χ(2) test, with a significance level of 5%, was used to compare the prevalence of alveolar domes in the maxillary posterior teeth and, considering the same teeth, to verify the difference in the prevalence of dome-shaped phenomena between the roots. RESULTS: The prevalence of alveolar domes present in the first pre-molars was statistically lower as compared to the other maxillary posterior teeth (p<0.05). No statistically significant difference was observed in the prevalence of alveolar domes between the maxillary first and second molars. Considering the maxillary first and second molars, it was observed that the palatal root presented a lower prevalence of alveolar domes when compared to the distobuccal and mesiobuccal roots (p<0.05). CONCLUSION: The present study coined the term 'alveolar dome', referring to the anatomical projection of the root into the floor of the maxillary sinus. The maxillary first and second molars presented a greater prevalence of alveolar domes, especially in the buccal roots, followed by the third molars and second pre-molars. Although the periapical radiograph is a two-dimensional method, it can provide dentists with the auxiliary information necessary to identify alveolar domes, thus improving diagnosis, planning, and treatment.

Ossifying fibroma: report on a clinical case, with the imaging and histopathological diagnosis made and treatment administered.

The aim was to report on a case of ossifying fibroma, consisting of a benign fibro-osseous lesion characterized by slow growth and proliferation of fibrous cellular tissue, bone, cement or a combination. A 29-year-old male patient was attended at a hospital, after he had suffered a car accident. During the clinical examination, increased volume in the region of the right side of the mandible was observed, and a fracture in the middle third of the face was suspected. The tomographic examination showed an image suggestive of fracturing of the left-side zygomatic complex, without displacement, and with a well-delimited radiopaque image of the mandible. The patient was sent to a hospital where panoramic radiography, posteroanterior radiography of the face and teleradiography were performed in order to better document the case. An incisional biopsy was performed. Histopathological examination showed the presence of a benign bone lesion suggestive of ossifying fibroma. Surgery was performed in order to completely remove the lesion, with fixation using a reconstruction plate. A new anatomopathological examination confirmed the diagnosis.

Relatar um caso de fibroma ossificante, uma lesão fibro-óssea benigna caracterizada por crescimento lento e proliferação de tecido celular fibroso, osso, cemento ou uma combinação.Paciente do sexo masculino, 29 anos, foi atendido em um serviço de emergência, após sofrer um acidente automobilístico. Durante o exame clínico observou-se um aumento de volume na região mandibular direita e suspeita de fratura no terço médio da face. O exame tomográfico demonstrou imagem sugestiva de fratura do complexo zigomático esquerdo, sem deslocamento, e imagem radiopaca bem delimitada na mandíbula. O paciente foi levado para o hospital, onde foram feitos uma radiografia panorâmica, PA de face e telerradiografia para melhor documentação do caso. Foi feita uma biópsia incisional. O exame histopatológico teve como resultado lesão óssea benigna, sugestiva de fibroma ossificante. Fez-se uma cirurgia para remoção completa da lesão e fixação com uma placa de reconstrução. O novo exame anatomopatológico confirmou o diagnóstico.